1. Technology Field
The present invention relates to a controller. More particularly, the present invention relates to a controller capable of preventing spread of computer viruses designed in an automatic executing file, a storage system and a method thereof.
2. Description of Related Art
Along with the widespread of digital cameras, mobile phones, and MP3 in recently years, the consumers' demand to storage media has increased drastically too. For example, a flash drive is a portable storage device using an NAND flash memory as the storage medium.
As the portable storage devices are widely used, it is discovered that more and more computer viruses can spread via the portable storage devices. Taking the flash drive as an example, as long as the flash drive infected by the viruses is plugged into a computer host, the computer host itself is also infected by the viruses, which may cause a serious damage. For example, the computer viruses spreading via the flash drive rewrites a content of an automatic executing file, and when the flash drive is plugged into the computer host, the computer host may automatically execute the content of the automatic executing file, so that the computer virus hidden in the flash drive may infect the computer host.
Once the computer host is infected by the computer virus, the computer virus then resides in processing programs of an operating system of the computer host, and the computer virus can detect an event recorder to get to know a current operating state of the computer host. Then, when another flash drive is connected to the computer host, the operating system automatically notifies such variation to the event recorder, and the computer virus can detect that the flash drive is connected by detecting the event recorder, so that the computer virus tries to copy itself to the connected flash drive. Since the flash drive is generally set to a readable and writable mode, the computer virus can be successfully written into the connected flash drive to modify the automatic executing file and write the related virus program.
Accordingly, as the portable storage devices are widely used for data exchanging among users, such type of computer viruses is quickly spread and causes a chain infection.
Nothing herein should be construed as an admission of knowledge in the prior art of any portion of the present invention. Furthermore, citation or identification of any document in this application is not an admission that such document is available as prior art to the present invention, or that any reference forms a part of the common general knowledge in the art.